Valve construction for aerosol dispensers of high solids slurries



Feb. 1964 D. c. GEARY ETAL 3,

VALVE CONSTRUCTION FOR AEROSOL DISPENSERS F HIGH SOLIDS SLURRIES FiledAug. 4, 1960 l i u i i i u 3/ Z 2! I f ii W 2a 3 Ex .19 1 22 i T r hlifl [i i k I y H INVENTORS DANIEL C. GEARY ROBERT W.GAINE$ BVM A TTORNEVUnited States Patent 1 3,121,517 VALVE :CGNSTRUQTKQN FQR AEROSOL DIE-PENSERS Gi HEGH SGLIDS ESLURRHES Daniel C. Gear-y, Westwood, N.J., andRobert W. Gaines,

Dar-ion, Conn, assigncrs to Union Carbide Corporation, a corporation ofNew York Filed Aug. 4, H60, Ser. No. 424% 4 Claims. (Cl. 222-694) Thepresent invention relates to a Valve for dispensing fluids and fluidizedsolids from pressurized aerosol container's and more particularly to avalve capable of dispensing high solids slurries containing as much aspercent or more by weight of solid particles having diameters as largeas 100 microns or more.

Pressurized aerosol containers are currently used to package anddispense a wide variety of fluids and fluidized solids materials. Thevalve included in these containers must be reliable, safe and, due tothe disposable nature of such containers, should be easily manufacturedand low in cost. in the most common type aerosol dispenser, thecontainer is a hollow cylinder, tightly closed at one end, with theassembly comprising the valve mechanism arranged to form the other endof the container. For convenience, one end will hereafter be called thetop or upper end and the other will be called the bottom or lower end ofthe container, although the container can be employed in any position.An annular shaped mounting cup, usually a metal stamping with an outeredge adapted to be tightly crimped over the top end opening of thepressure container, forms the valve support. A vertically positionedhollow cylindrical valve chamber with an open top and a closed bottom iscrimped, swaged or otherwise affixed to the axial center of saidmounting cup on the underside to support and guide the moving parts ofthe valve. Between the upper circular rim of said valve chamber and theunderside of the mounting cup, an annular sealing gasket of rubber,flexible plastic material or the like having a centrally locatedcircular opening therethrough is held in a fixed position but with theinner edge surrounding the circular opening free to be depressed in adownward direction. The moving parts of the valve comprise a verticallydisposed cylindrical stem, reciprocally moveable in a centrally locatedopening in the mounting cup, having a longitudinal axial bore extendingpart way therethrough from its upper end, at least one lateral orificeconnecting the axial bore with the stem exterior surface to form a valvestem inlet port, an increased diameter portion or shoulder locatedbeneath said lateral orifice and an increased diameter portion bevelleddownwardly and inwardly located above said lateral orifice; a coilspring disposed around said stem, lightly loaded in compression betweenthe closed bottom of the hollow cylindrical valve chamber and theincreased diameter portion :or shoulder on said stem to maintain thelateral orifice in a registering position within the sealing plane ofthe annular sealing gasket with the stem shoulder immediately beneathsaid gasket and the stem bevelled portion immediately above said gasketand, on the upper portion of the valve stem, a valve stem head, havingpassages to conduct material to be dispersed from the stem bore to theexterior of the dispensercontainer. One or more ports through the bottomof the cylindrical valve chamber provide passage means between theint'orior of the container and the interior of said valve chamber, and ahollow feeder or dip tube connected between the valve chamber bottomportion and a point near the bottom of the container assures fullfeeding of the contents to the dispensing valve assembly.

An aerosol dispenser of the type described above is operated by exertingdownward pressure on the valve stem head, which causes the bevelledportion oi? the "ice valve stem to depress the inner rim of the sealinggasket downwardly and outwardly away from the lateral orifice in thestem, thereby uncovering the orifice and establishing a continuous iiowpath from the container interior through the feeder tube, the portsthrough the bottom of the cylindrical valve chamber, the interior of thecylindrical valve chamber, the stem lateral orifice, the stemlongitudinal bore and the passages of the valve stem head to theexterior of the container. The contents of the container are forced, bycontainer internal pressure, along this flow path and dispensed throughthe valve stem head. When the valve stem head is released, the resilientaction of the valve coil spring returns the valve stem to its closedposition.

Valves of the above described type have been found to be generallyunsuitable for dispensing aerosol powder formulations. It has been foundthat the powder agglomerates, clogs the valve orifices and blocks thesealing action of the valve sealing gasket. Powders which are abrasivealso tend to Wear channels into the sealing portions of the valve withcontinued use, causing the propellant fluid to escape from the containerwhen the valve stem is in the closed position. Due to the arrangement ofthe valve components, the valve stem lateral orifice is inaccessible forremoving agglomerated particulate matter when in either the closed oropen position. Valve malfunctions of the type described above becomemore pronounced and more frequent when such valves are used to dispensecontents with more than 10 percent of solid particles and particularlywhere the particles have diameters greater than 10 microns.

The apparatus of the present invention obviates the foregoingdifiiculties by providing a universal powder valve comprising a uniquearrangement and disposition of valve components which, in operation, candispense powder aerosols containing 25 percent or more of solidparticles having diameters up to microns or more without clogging orleaking. The apparatus is also very effective for dispensing liquids,dispersions and the like.

The apparatus of the present invention also comprises a valve havinga'stem lateral orifice in a position accessible for cleaning when saidvalve is in the closed position.

The invention also comprises novel details of construction and novelcombinations of components, together with other features and resultswhich will be more apparent from the following description. The drawingsmerely show and the description merely describe-s a preferred embodimentof the present invention which is given by way of illustration.

In the drawings:

FIGURE 1 is a partially sectional view of the upper portion of anaerosol container showing a universal powder valve, according to thepresent invention, in the valve-closed position and FIGURE 2 is apartially sectional view of the upper portion of an aerosol containershowing the valve of FIGURE 1 in the valve-opened position.

in the embodiment of the drawings, a pressure container 11 is surmountedby a mounting cup 13, of metal, plastic or the like, have a centrallylocated circular opening therethro-ugh, tightly fitted to said pressurecontainer by a rolled and crimped outer edge. A hollow cylindrical valvechamber 1-5, having an open top and. a closed bottom with ports 1-6extending through said bottom, is pressfitted or 'swaged into acentrally disposed. circular, upwardly expanded portion of mounting cup13. An annular valve seal 17 of rubber, plastic or the like, having acentrally located circular opening therethrough, is arhanged in theupwardly expanded portion of mounting cup 13 and is rigidly supported onits underside by a valve seal retainer 19 which is an annular shapedrigid component of metal or the like, having a centrally locatedcircular opening therethrough. Valve seal 17 and valve seal retainer 19are held in fixed position between the mounting cu-p underside and theupper rim of valve chamber in relative positions to bring approximatelyequal diameter, centrally located circular openings in mounting cup 13,the valve seal and the valve seal retainer into concentric registeringpositions.

The valve movable components comprise a vertically disposed cylindricalvalve stem 21, reciprocally movable through the centrally locatedopenings in mounting cup 13, valve seal 17 and valve seal retainer 19,having a longitudinal passage 25 extending from the valve stem upper endfor somewhat more than one half the stem length, a lateral orifice 23connecting valve stem passage 25 with the stem exterior surface to forma valve stem inlet port and a raised diameter portion or shoulder 22; avalve stem spring 24, disposed around the lower portion of said valvestem, lightly loaded in compression between the closed bottom of valvechamber 15 and the underside of stem shoulder 22 to maintain the uppersurface of shoulder 22 in compressive contact with the underside ofvalve seal retainer 19; and, on the upper portion of valve stem 21,valve dispensing head 29, having connected passages 31 and 33connecting, respectively, to valve stem passage 25 and to the exteriorof the container-dispenser. A hollow feeder tube 35, is press fittedover the lower portion of valve chamber 15 and extends downwardly to apoint near the bottom of container 11 to assure full feeding of thecontainer contents to the dispensing valve assembly.

To operate the embodiment shown in the drawings, downward force isapplied to valve dispensing head 2 causing valve stem 21 to moveslideably through valve seal 17 and the openings in mounting cup 13 andvalve seal retainer 19. Valve stem shoulder 22 compresses valve stemspring 27 against the bottom of valve chamber 15, thereby developing avalve closing force which acts upon removal of the downward force on thevalve dispensing head. When valve stem 21 has been depressed to aposition where valve stem lateral orifice 23 is beneath the sealingplane of valve seal 17, the valve is open and a continuous flow path isestablished from the container interior through the feeder tube, ports16, the interior of valve chamber 15, stem lateral orifice 23, stempassage 25, and dispensing head passages 31 and 3-3. The contents of thecontainer are forced, by container internal pressure, along this flowpath and dispensed through dispensing head passage 33. When downwardforce is removed from dispensing head 29, energy stored in spring 27returns the valve stem to the closed position.

Particular attention is directed to the location of the stem lateralorifice in the drawings. When the valve is in the closed position, asshown in FIGURE 1, the stem lateral orifice is outside the valve chamberand container, in a position accessible for visual inspection andcleaning. In addition, by means of this arrangement, an unbrokenperipheral surface of valve stem 21 is presented to the sealing face ofvalve seal 17, with the valve in either the closed or open position.

Valve seal 17, held firmly in place by valve seal retainer 19, effects awiping action against the valve stem as it is moved reciprocally bewteenthe closed and open positions. The seal thus acts, during the valveclosing movement, to wipe the stern surface clear of any agglomeratedmate-rial which may collect around lateral orifice 23- while the valveis in the open position. The valve seal retainer 19, in addition toholding the valve seal firmly to effect the stem wiping action, holdsthe seal in contact with the underside of mounting cup 13, preventingexcessive deflection of the seal center portion and excluding thepossibility of agglomerated or comrninuted material from collectingbetween the valve seal and mounting cup and deflecting the sealsufficiently to cause leakage of the aerosol propellant.

In the preferred embodiment of the present invention, the valve stemlength and travel distance and the position of the valve stem lateralorifice are selected to obtain passage of the lateral orifice to thecontainer exterior before the stem has moved more than one-quarter toone-third of the total distance of travel between the open and closedpositions, This arrangement minimizes the possibility of inadvertentloss of contents from the valve sticking in the open or partly openposition due to agglomerated powder build-up between the valve stemshoulder and the valve seal retainer or valve seal.

A further improvement over known valves is comprised in the downwardlyextended lower or container-interior end of the vertically disposedvalve stem which, during the valve opening movement, passesconcentrically through valve stem spring 27 to break up agglomeratedmaterial on and around the spring coils, thereby maintaining a clearflow path through valve chamber 15.

Those skilled in the art will recognize that certain modifications maybe made to the above-described embodiment of the present inventionwithout departing from the basic concept. For example, the wiping actionand sealing function of the valve seal could be accomplished bysubstituting an O-ring gasket of rubber or the like, retained in arecess integral with the mounting cup.

It will also be apparent to those skilled in the art that the embodimentshown in the drawings can be operated with the container in any positionand that for continued use in an inverted position improved operationwill result if the feeder tube 35 is omitted.

While, in the foregoing description, certain specific details andoperative steps have been set forth, together with certain suggestedmodifications, it will be obvious that considerable variation may bemade in these without departing from the spirit of the presentinvention.

The foregoing description has been given for clearness of understandingonly, and no unnecessary limitations should be understood therefrom.

What is claimed is:

1. A valve for dispensing fluidized material containing as much as 15percent or more by weight of solid particles having diameters as largeas microns or more from a pressurized aerosol container comprising, incombination, a valve mounting cup forming a wall portion of saidcontainer and having an opening therethrough, an elongate valve stemextending through said mounting cup opening with an end interior and anend exterior of said container, reciprocally moveable between a firstposition and a second position, having a longitudinal internal passageextending from the stem exterior end for less than the stem length, atransverse passage connecting said longitudinal internal passage to thestem exterior located in said stem to be exterior of the pressurizedcontainer when the stem has travelled one-quarter to onethird from saidsecond position towards said first position and interior of thepressurized container when the stem is in said second position, andmeans on said stem to re tain said stem partially within the container;a valve chamber having an open end and a closed end with ports extendingtherethrough attached to the interior side of said mounting cup tosupport and guide said stem; resilient means compressively loaded toexert force between said closed end of said valve chamber and the stemretaining means and means to effect sealing between the pressurizedinterior and exterior of said container against the periphery of saidstem and to effect wiping action on the peripheral surface of said stemduring reciprocal stem movement, wherewith which combination saidfluidized material is substantially completely dispensed from saidaerosol container, the agglomeration of said solid particles, with thesticking of said stem periphery in said sealing means, and with theconsequent loss of pressure, being prevented by the above-recitedlocation of said transverse passage and the above-recited extent oftravel of said valve stem.

2. A valve in accordance with claim 1 in combination with means toconnect said valve chamber with the lowest practical ievel of saidaerosol container.

3. A valve in accordance with claim 1 in which said means to effectsealing and wiping comprises, in combination, a valve seal having anopening therethrough located in registering relationship with theopening in said mounting cup and a valve seal retainer arranged contiuously to said valve seal and having an opening therethrough located inregistering relationship with the respective openings in said mountingcup and said valve seal.

4. A valve in accordance with claim 1 in which said resilient meanscomprises a coil spring and said valve &

stem end interior of said container extends concentrically substantiallythrough said coil spring When the stem is in said second position.

References Cited in the tile of this patent UNITED STATES PATENTS2,721,010 Meshberg Oct. 18, 1955 2,812,884 Ward Nov. 12, 1957 2,837,249Meshbe rg June 3, 1958 2,858,053 \Valdhen Oct. 23, 1958 2,886,217 ThielMay 12, 1959 2,932,432 Beard Apr. 12, 1960 2,953,284 Prussin 'et a1Sept. 20, 1960

1. A VALVE FOR DISPENSING FLUIDIZED MATERIAL CONTAINING AS MUCH AS 15PERCENT OR MORE BY WEIGHT OF SOLID PARTICLES HAVING DIAMETERS AS LARGEAS 100 MICRONS OR MORE FROM A PRESSURIZED AEROSOL CONTAINER COMPRISING,IN COMBINATION, A VALVE MOUNTING CUP FORMING A WALL PORTION OF SAIDCONTAINER AND HAVING AN OPENING THERETHROUGH, AN ELONGATE VALVE STEMEXTENDING THROUGH SAID MOUNTING CUP OPENING WITH AN END INTERIOR AND ANEND EXTERIOR OF SAID CONTAINER, RECIPROCALLY MOVEABLE BETWEEN A FIRSTPOSITION AND A SECOND POSITION, HAVING A LONGITUDINAL INTERNAL PASSAGEEXTENDING FROM THE STEM EXTERIOR END FOR LESS THAN THE STEM LENGTH, ATRANSVERSE PASSAGE CONNECTING SAID LONGITUDINAL INTERNAL PASSAGE TO THESTEM EXTERIOR LOCATED IN SAID STEM TO BE EXTERIOR OF THE PRESSURIZEDCONTAINER WHEN THE STEM HAS TRAVELLED ONE-QUARTER TO ONETHIRD FROM SAIDSECOND POSITION TOWARDS SAID FIRST POSITION AND INTERIOR OF THEPRESSURIZED CONTAINER WHEN THE STEM IS IN SAID SECOND POSITION, ANDMEANS ON SAID STEM TO RETAIN SAID STEM PARTIALLY WITHIN THE CONTAINER; AVALVE CHAMBER HAVING AN OPEN END AND A CLOSED END WITH PORTS EXTENDINGTHERETHROUGH ATTACHED TO THE INTERIOR SIDE OF SAID MOUNTING CUP TOSUPPORT AND GUIDE SAID STEM; RESILIENT MEANS COMPRESSIVELY LOADED TOEXERT FORCE BETWEEN SAID CLOSED END OF SAID VALVE CHAMBER AND THE STEMRETAINING MEANS AND MEANS TO EFFECT SEALING BETWEEN THE PRESSURIZEDINTERIOR AND EXTERIOR OF SAID CONTAINER AGAINST THE PERIPHERY OF SAIDSTEM AND TO EFFECT WIPING ACTION ON THE PERIPHERAL SURFACE OF SAID STEMDURING RECIPROCAL STEM MOVEMENT, WHEREWITH WHICH COMBINATION SAIDFLUIDIZED MATERIAL IS SUBSTANTIALLY COMPLETELY DISPENSED FROM SAIDAEROSOL CONTAINER, THE AGGLOMERATION OF SAID SOLID PARTICLES, WITH THESTICKING OF SAID STEM PERIPHERY IN SAID SEALING MEANS, AND WITH THECONSEQUENT LOSS OF PRESSURE, BEING PREVENTED BY THE ABOVE-RECITEDLOCATION OF SAID TRANSVERSE PASSAGE AND THE ABOVE-RECITED EXTENT OFTRAVEL OF SAID VALVE STEM.